enable large file support when available

You-Sheng Yangrequested to merge
vicamo-guest/dash:for-upstream/enable-large-file-support into debian/master

A path expansion issue was firstly found while installing python3-docutils/sid on armel/armhf/mips/mipsel, and has been reported as bug 916225. Dash failed to expand the line for exe in /usr/share/docutils/scripts/python3/* in python3-docutils' postinst script, and failed the installation. With some more investigation into this issue, I got following trace messages for dash:

Tracing started.
waitforjob(%0) called
pid 15608, evaltree(0xfffef918: 0, 1) called
evalcommand(0xfffef918, 1) called
expandmeta(0xfffef948, 3) called
expandmeta(0xfffef968, 3) called
expandmeta str: /usr/share/vim/*
expmeta(/usr/share/vim/*, 16, 0) called
expmeta metaflag 1
expmeta opendir(/usr/share/vim/)
expmeta begin loop
expmeta break loop: readdir error, errno 75
expmeta end loop
evalcommand arg: ls
evalcommand arg: /usr/share/vim/*
searchexec "ls" returns "/usr/bin/ls"

/usr/share/vim/* here shows such expansion failure doesn't only occur to python3-docutils' postinst script, but also many other places. The errno 75 (EOVERFLOW) shows readdir() call may fail when one of the field to return cannot be represented correctly, so large file support should be enabled whenever available.

This change adds AC_SYS_LARGEFILE to configure.ac.

Merge request reports